German police have searched the headquarters of Deutsche Bank in connection with a money-laundering probe.
The local prosecutor's office in Frankfurt said it is "the first time" that a German bank has been involved in such an investigation.
“This is an investigative measure by the Frankfurt public prosecutor’s office in connection with suspicious activity reports filed by the bank," it said in a statement on Friday.
"Deutsche Bank is fully cooperating with the authorities,” prosecutors added.
German media reported that the investigation is focused on whether Germany's largest bank failed to alert authorities soon enough about suspicious transactions by one of its customers.
Germany's Federal Financial Supervisory Authority (BaFin) has not commented on the investigation.
Last year, the authority had reminded Deutsche Bank to step up its efforts to combat money laundering and financial crime.
The Frankfurt-based institution was also searched in 2019 in connection with an investigation into Denmark's Danske Bank.
Deutsche Bank subsequently agreed to pay a fine of €13.5 million for its delay in making the disclosures.